[media] i2c/s5k4ecgx: fix printk format warning

Fix printk format warning for size_t variable:
drivers/media/i2c/s5k4ecgx.c:346:2: warning: format '%d' expects type 'int', but argument 4 has type 'size_t'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>